Targeted drug delivery under MRI guidance.

The main goal of local drug delivery is to increase the concentration of a specific therapeutic agent in a target tissue with minimal nontarget distribution. Compared to systemic therapy, local drug delivery provides a high level of therapeutic efficacy with minimal systemic effects. The current primary imaging modality for drug delivery has been x-ray angiography, but it has major limitations including anatomical ambiguity and inability to visualize the targeted tissues. Due to these inherent problems, MR guidance has been explored as an alternative imaging modality for guiding and monitoring of drug therapy. Recently, interventional MR (XMR) systems have been implemented that have both dual x-ray and MRI capabilities in a single suite and allow for real-time interventional procedures to be performed in a clinical setting. In cases where drug delivery is required, this system provides a significant leap for catheter-based therapies. Although clinical drug delivery procedures utilizing MR guidance are still in the early stages of development and application, recent technological advances should help further promote the adoption of such procedures. This review covers the emerging techniques of drug delivery using MR guidance.